Connecting device for electric discharge tubes



P. SCHOUWSTRA 1,933,344

CONNECTING DEVICE FOR ELECTRIC DISCHARGE TUBES Oct. 31, 1933.

Filed Dec. 16, 1929 Patented Oct. 31, 1933 v 1,933,344

UNITED STATES PATENT OFFICE CONNECTING DEVICE FOR ELECTRIC DISCHARGE TUBES Pieter Schouwstra, Eindhoven, Netherlands, as signor, by mesne assignments, to General Electric Company, a corporation of New York Application December 16, 1929, Serial No. 414,546, and in the Netherlands February 7, 1929 2 Claims. (Cl. 173328) The invention relates to electric discharge tion. Beyond this portion it may be contracted tubes and is of particular importance in the by means of a wire, thread or ribbon and prefdomain of discharge tubes destined for the radiaerably be clamped against the wall of the tube. tion of light. in this case a boss provided at the end of the It is often dangerous to come into contact envelope prevents this wire or ribbon from slidwith parts of an electric discharge tube which ing oii the envelope. are not enclosed in its wall or with the con- In order that the invention may be more clear ductors whereby the current is supplied to the ly understood and readily carried into effect it tube. Light radiating tubes, which are utilized will be described more fully with reference to 10 on a large scale for advertising purposes, mostly the accompanying drawing which represents, by operate at a high tension which sometimes Way of example, some embodiments of a device amounts to some thousands of volts. If such according to the invention. In the drawing: tubes are not arranged in such manner that any Figures 1 and 2 relate to the same construcpossibility of touching them is excluded, it must tion, in Figure 1 a supply wire is connected to a 15 not be omitted to take safety measures in order tube and in Figure 2 both parts are separately to avoid a contact with parts being under tenrepresented. sion. This is a great drawback of the use of Figure 3 represents another embodiment of such tubes at points located within the reach of the invention. human hands such as shopwindows and other In the Figures 1 and 2 only the part 1 of an 20 points where the use of transparencies or of electric discharge tube is visible. This tube may, luminous scrip is in place. for example, be filled with dilute neon or other Another problem is the suitable attachment gas and may have the shape of a rod or be bent of the conductors to the tubes fed by them. The to a character or other sign. The part 2 is a leading-in wires sealed into the wall of the tube chamber which contains an electrode. At 3 the 25 often extend some distance outside the latter tube passes into the luminous portion proper. and in this case they are connected with the The electrode, which is not represented, is elecaid of simple connecting means to the feeders. trically connected to a cap-shaped contact mem- In this case there exists the danger that such her 4 provided with a contact pin 5. On the part pp y Wire breaks close to the glass wall so 2 of the tube may be slid an envelope 6. As

30 tha t e b although I the Test Perfectly appears from Figure l, the contact pin 5 is inintact, becomes unfit for use. serte'd into a resilient bush 7 provided on an The invention concerns a connecting device end-piece8 which is embedded in the envelope whereby the said two problems are simultaneand to which is secured a, preferably flexible,

. ously brought to a solution and which in other current supply wire 9. This wire is surrounded 35 r p l ff ds a v n a m y ppear by an insulation 10 which is continued byastockfrom the following specification. ing-shaped envelope 6. The material of this In the device according to the invention, a insulation should preferably be elastic 'so that current supply wire or a plurality of such wires the stocking 6 elastically closes around the wall is or are surrounded by an envelope which exof the tube. This material may be constituted,

40 tends on part of the tube. This envelope may for example, by rubber. The internal diameter consist entirely or partly of an insulating mated1 of the stocking is so chosen as to be slightly rial which serves as an insulation of the current smaller than the external diameter of the tube supply wire and/or of parts of the tube which (12 (Figure 2), owing to which not only a discome under tension. To such a current supply placement of the contact pieces of the tube and 45 wire may be secured an end-piece which is enof the wire relatively to one another is rendered closed in the envelope and which, preferably by difficult but also the additional advantage is means of one or more resilient members, is elecobtained that penetration of moisture is avoided, trically connected to'a contact member secured the danger that in consequence thereof on the to the tubes wall of the tube may be produced a conducting 50 In many cases it is advisable that the enlayer connected to the parts under tension, being velope should elastically close around the tube. thus eliminated.

At the ends where the leading-in wires are An embodiment which satisfies still higher found the tube often has a widened portion. electric and mechanical requirements, is shown In this case it is very advantageous that the in Figure 3. In this construction the stocking- 55 envelope should extend pastthis widened porshaped envelope 6 extends as far as past the 11, which is prevented from sliding off the envelope by .a boss 12 at the end of the envelope. A larger length of the tube is consequently protected while the mechanical connection of the tube and the envelope isproof against pulls exerted thereon. A helically wound spring 13 establishes the electric connection between the contact member 4 of the tube and the endpiece 8 of the current supply wire 9. If the insulating supply wire whereby the connection with a transformer or other source of current is established does not lead directly to the source of current, it may be provided at its other end with a contact device, owing to which it may be connected to a lengthening-piece which carries a device similar to the one described, an electrically and, if necessary, also mechanically protected coupling being thus obtained. It will be evident that the invention is not only of importance for luminous tubes but can also be applied to other discharge tubes. Thus, for example, rectifiers whose anodes are sometimes enclosed in separate extensions may be provided with connecting means according to the above described principle, in which event the envelope extends on part of these extensions. Alternately, a plurality of contacts may be present in a single holder. Such is the case, for example, if the electrode in question is an incandescent cathode or if a plurality. of electrodes are led out of the tube on the same side.

Discharge tubes provided with a device according to the invention, have at their surface no parts being under tension and they may consequently be constructed in such manner that coming into contact with them is under all condtions without any danger, particular safety measures being consequently made superfluous. The construction according to the invention affords the additional great advantage that the tubes may be given almost any desired position with respect to thesource of current and that this position can be altered at will without any necessity of making alterations in the installation.

What I claim is:

1. A connecting device for an electric discharge tube having portions of difierent sizes, the device comprising a cable comprised of at least one current supply-wire surrounded by insulating material, said insulation extending beyond the portion of the tube of larger size as far as the portion of smaller size, and an electrical contact member between said supply wire and an electrode of said tube, said member being permanently connected to said wire and detachably connected to said electrode. 4

2. A connecting device for an electric discharge tube having a widened end portion, the device comprising a cable comprised of at least one current supply wire surrounded by insulating material, said insulation resiliently closing around and extending past said widened end portion, means for constricting said insulation beyond said widened portion, and a boss at the end of said insulation for preventing said constricting means from sliding off.

PIETER SCHOUWSTRA. 

